Design of series-connected thyristor switch and synchronous triggering circuit

In order to meet the requirement of pulsed power source on high voltage and large current switches，a series-connected thyristor switch with a rated voltage of 10 kV and a rated current of 500 A was developed the traditional voltage sharing method. According to the principle of thyristor trigger, a trigger system was developed for synchronous triggering multiple thyristors. As to generate low-voltage pulse with variable pulse widths, the trigger system used an IGBT switch to cut the DC voltage. In the trigger system, the voltage amplitude of the pulse was increased and the synchronous trigger signals were generated through some isolated pulse transformers. Finally, the thyristor trigger system and the series-connected thyristor switch were tested, Showing that the trigger system could produce multi-channel synchronous trigger signals with a voltage of 20 V, a current of 1 A, a pulse repetition rate of 100 Hz and pulse durations from 30 s to 60 s. Static voltage fluctuation and active voltage fluctuation of the series-connected thyristor switch were small, indicating it could reliably work under the condition of high voltage and large current.